Alternating-current regulator.



No. 731,430. PATENTED JUNE-2s, 1903 0. 0. 0HENEY & W. J. LLOYD. .7ALTERNATING CURRENT REGULATOR.

APPLICATION IILED JULY 18. 1902.

I0 KODEL.

a z c 2 6 CUMMINGS G. CHESNEY SIM/['01s WILLIAM J. LLOYD UNITED STATESPatented June 23, 1903.

PATENT QFFICE.

CUMMINGS O. CHESNEY AND WILLIAM J. LLOYD, OF PITTSFIELD, MASSACHUSETTS.

ALTERNATlNG-CURRENT REGULATOR.

SPECIFICATION forming part of Letters Patent No. 7 31,430, dated June23, 1903.

Application filed July 18,1902. Serial No. 116,013. (No model.)

To ctZZ whom it may concern.-

Be it known that we, CUMMINGS O. CHES- NEY and WILLIAM J. LLOYD,citizens of the United States, residing at Pittsfield, Berkshire county,Massachusetts, have invented certain new and useful Improvements inAlternating-Current Regulators, of which the following is a full, clear,and exact description.

Our invention relates to improvements in alternating-current regulators,and has for its object to produce an efticient apparatus for regulatingthe current-flow in an alternating-current circuit, being particularlyintended for use with arc-lights or incandescent lights when run inseries from a constant-potential source of supply.

By theme of this apparatus the current can be maintained substantiallyconstant in a branch supplied from a constant-potential source, althoughsaid branch contains a varying load of lamps in series.

The following is a description of an appa- .ratus embodyingour'invention, reference be ing had to the accompanying drawings, inwhich- Figure 1 shows it in side elevation. Fig.

2 is a horizontal section of the apparatus.

Fig. 3 shows the wiring and connections. Fig. 4 shows a detail inperspective.

Referring more particularly to the drawings, A represents a magneticcircuit having polar projections P P, about which are coils 0 C -Withinthe polar projections P P is a magnetic core D, mounted in the bearingsE so as to revolve between the polepieces P P. This core D is in theform of a shuttle-armature and has upon it the coil G which, as shown inFig. 3, is in series with the coils C O and has a number of turns equalto the sum of the turns in those two coils. Upon the shaft Gr ofthe coreD is mounted a sector H, over which passes a rope I, connected to aweight 'W. The pole-pieces P P have slots in their faces, in which liecoils K, which are windings closed upon themselves, so as to form closedconductingcircuits. These windings being in aplane parallel to the linesof force due to the coils 5o 0 C are not affected thereby, except byleakage therefrom, but are affected by the lines of force due to thecurrent in the coil 0 when that coil is turned so as not to be at rightangles to the line joining the polar centers. In the form shown thecoils 0, C and O are in series with one another and are also in serieswith the lamp-circuit L L, supplied with the current from theconstant-potential mains h M The instrument controls the amount ofcurrent flowing to the lamp-circuit L L by varying the amount ofinductance in the circuits. With the parts in the position shown in thedrawings the inductance is greatest, since it depends on the number oflines of force threading the winding, and it is evident that thegreatest number of lines will thread the windings when theyareallgeuerating lines of force in the same direction. In'the operation ofthe apparatus'the movable magnet tends to arrange itself so that thelines of force will have the shortest direct path from one pole toanother of opposite character. The core D, therefore, tends to setitself in the position shown in Figs. 1 and 3, which tendency is to acertain extent counterbalanced by the weight WV. If the load in thecircuit is such that the parts assume the position shown and additionalresistance or inductance is inserted at L L, the current-flow tends tofall, due to the increased resistance or inductance. This lessens thelines of force to be generated in the regulator by the coils C, 0 and Cand consequently lessens the force, tending to hold the core in theposition shown. Immediately the weight W descends, rotating the armatureD. The rotation of the armature D decreases the number of lines of forcethreading the coils C O 0 thereby reducing the inductance in the circuitdue to the action of these coils, thus allowing more current to flowthrough the regulator and through the circuit L L. In this way with theinductance and magnetic attraction working against each other and by theselection of a suitable controlling force, such as a weight W, thecurrent can be maintained constant in the lamp-circuit L L, or bysuitable adjustments the current can be made to assume any desired valuefor any fixed condition of the circuit L L or varied independently. Whenthe circuit L L is loaded to the maximum value, the armature D would berotated through one hundred and eighty degrees. In this position theflux due to the coil would neutralize the flux due to the coils O and Oand the regulator would have no ind uctanceand would therefore offerpractically no resistance to the fiow of the current. In order to getthe highest efficiency at full load, the short-circuited coils K areembedded in the polar faces and arranged at right angles to the mainstationary coil 0 C These coils K are shown in position in slots in thepolar faces. The operation of these coils is as follows: When thearmature is in the position shown in Fig. 1, the lines of force have astraight path through the iron, and the coils K K in effect are parallelwith the lines of force, and consequently no electromotive force is setup in them and there is no flow of current therein. When, however, thearmature is rotated from the position shown in the figures, the lines offorce generated by the coil C cuts the shortcircuited coils K, causingthe currents to flow therein, thus neutralizing the self-induction ofthe movable coil 0 The maximum effect occurs when the armature is movedninety degrees from the position shown in the figures. When the armatureis rotated one hundred and eighty degrees from the position shown, thecurrent flowing through the movable coil 0 is exactly opposed to thecurrent flowing through the stationary coils G 0 The normal tendency isto drive the lines of force out at the edge of the field, causing whatis generally understood as a stray field. This stray field causes localself-induction in both the stationary and the movable coils O O O andthese lessen the output of the regulator. The short-circuited coils,however, are in the position so as to counteract the effect of thisstray field. The stray field cuts the shortcircuited coils K, causingthe currents to fiow therein, which neutralizes the localself-induction.

Our invention is capable of being embodied in various forms ofapparatus, and we do not,

therefore, intend to limit it to the precise embodiment shown.

What we claim is- -1. In a regulator, in combination, a magneticcircuit, consisting of a fixed and a movable member, windings on both ofsaid members supplied from the same alternating-current source, and aclosed circuit fixed relatively to one member and in a plane parallel tothe lines of force due to the windings thereon.

2. In a regulator, in combination, a magnetic circuit consisting of afixed and a movable member, windings on one member in series with andsubstantially equal to those of the other, and means tending to overcomethe attraction of the current in the windings of one member for thecurrent in the other windings, and a closed circuit fixed relatively toone of said members and parallel to the lines of force due to thewindings thereon.

3. In a regulator, in combination, a cylindrical core, a second coreembracing said cylindrical core, the two cores being relatively movable,windings on each of said cores in inductive relation to each other,means tending to overcome the attraction of the currents in saidwindings, and a closed conducting-circuit fixed in non-inductiverelation to the winding on said second core.

4. In a regulator, in combination, a stationary magnetic member havingpolar projections and winding thereon, a movable magnetic member betweensaid polepieces, a Winding thereon, said winding being supplied from thesame source, means tending to overcome the attraction of said windings,and a closed circuited windinglying across the faces of said pole-piecesin a plane parallel to the axis of rotation of the movable member.

Signed at Pittsfield, Massachusetts, this 15th day of July, 1902.

CUMMINGS C. CHESNEY.

WILLIAM J. LLOYD.

Witnesses:

O. F. ADAMS, R. W. Pownn.

